Steam-boiler and furnace lining



(Model.)

C. MGMILLAN. Y STEAMBOILBR AND PURNAGE LINING.

No. 298,788. Patented Apr. 18, 1884.v

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STEAM-BOLER AND FURNAGE LlNlNG.

SPECIFICATION forming part of Letters Patent No. 296,768, (ated April l57 1884.

Application filed December S, 1879. Renewed March 16, 1882. Again renewed March il, l'Sl. (Model.)

To (LEZ whom t may concern/.-

Be it known that l, CHARLES MGMILLAN, of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Steam-Boiler-Furnace Linings, of which the following is a specification.

This invention relates to linings for protecting the crown'sheets of steamboilers from the destructive influences of the heat and flames of a furnace, and for supplying air to the products of combustion.

Heretofore bridge-walls have been provided with aperforated extension, through which the flames pass, and which conforms to and is in close contact with the boiler immediately over said wall, but at no other point,`and thereby affording no protection to the crowirsheets over the gratebars. Linings of brick, upon their under surface flat, but upon their upper surface concave, and conforming in shape and supported in contact with the crown-sheets over the grate-bars by means of steam-pipes entering the sides of the` boiler and passing under and upon the outside of the lining, have also been used; but these linings, though protecting the crownsheets diminish the effectireness of the heat upon the saine, and also the eveuness of temperature of the boiler, by reason of the necessarily increasing thickness given them on either side of and between the longitudinal center of the, boiler and the side wall of the furnace,`to have them hat upon their under surface. pipes supporting said linings not only strain the boiler-sheets, but are in a very short time, by reason oi their exposed position in the furnace, burned off, therebyr putting out the iire and letting the lining drop, unless otherwise supported. y

The object of this invention is to protect the crownsheets of a boiler immediately over the grate-bars from the destructive iniiuences of the burning fuel upon the same, and to main tain said boiler at substantially an even teniperature without strain upon the same or perceptibly diminishing the area of the fire-chamber. A further object is to conduct air from the outside of the furnace directly to the products of combustion, near the upper edge of and over the bridge-Wall, and finally to direct the current of air thus conducted downwardly l faces.

Furthermore, the steamat substantially-an oblique angle toward the rear end ofthe furnace.

In the accompanying drawings, in which similar letters indicate the saine parts, Figure lis a side elevation of a furnace, with parts Ybrolren away to show the attachment of my lining to the boiler and the relative position to the lire-Wall of the outlets to the air-ducts of the same. `liig. 2 is an end elevation of the saine. Fig. 3 is a similar view of a furnace, with parts broken away to show the band sus pending and holding in contact with the boiler the lining for the saine, and of a lining for the side Walls of the furnace, provided With perforations opening into the ash-pit, and the transverse perforations in the boilenlinings.

A represents the furnace, with the boiler B suspended in the saine; C, the fire-Wall, and D the grate-bars, all of Which are of the ordinaryy construction.

E is a lining of tiling, made'of one or a se ries of plates or pieces concave on their upper and convex on their lower surface, to correspond With the crown-sheets of a boiler, and of sufficient thickness, breadth, and length to effectually protect the crown sheets of the boilerl over the grate-bars from the corroding and destructive influences of the ilames, and

to admit of a series of longitudinal and transverse perforations between its opposite sur The lining E is secured to and in contact with the boiler by means of bolts e, as shown in Fig. 2, or by a band, f, entering said linings and passing over the boiler, to suspend them in contact therewith, as shown in Figs. l and 3, the band affording a convenient means when it is unnecessary or impractical to use the bolts, though in some cases bot-l1 may be used to relieve the strain upon the boiler resulting from the Weight of the lining. The plate or plates forming the lining are provided with a series of longitudinal perforations eX- tending from end to end, as vshovvn'in Fig. l, or from the front end of the furnace to an inlet a short distance from the front side of the bridgewall, provided With an elbow or tube, g', for directing the air to the naines at an 0b` lique angle toward the back of the furnace, so that the draft of the furnace will facilitate the introduction instead of retarding it, as would be the case if the tubes `vere turned in the op- IOO posite direction, or ata right angleto the plates. Although it is preferable to use th-ese tubes as described, because a better draft is thereby obtained through the perforations, yet it is obvious that they may be omitted, and the perforations in the plates be made to extend at an oblique angle instead thereof Without departing from the gist of my invention.

g2 are transverse perforations in the linings E, opening into the yperforations g, the purpose of which will be hereinafter fully explained.

F F are plates of tiling, forming linings for the side Walls of the furnace, and secured there- .to by bolts or other means. They may, however, be secured to a removable section of the furnace, as indicated in Fig. 3, so that When a larger fire-chamber is required they can be taken out, or vice versa when a smaller one for summer use is required. AThese plates eX- tend from the front of the furnace to the bridge- Wall, and from the bottom to the boiler-linings, to which they are neatly joined, and provided With a series of vertical perforations, j", leading from the ashpit, corresponding in number to the transverse perf'orations g2 in said linings, into which they open, so that heated air may be conducted from the ash-pit to the flames in the fire-chamber.

By my construction it will be seen that the tilings forming the lining of the boiler are not only made a means of conveying air to the fiames, but a medium to absorb and conduct the heat from the fire-chamber direct to the boiler, at the same time retaining a sufficient quantity to maintain the contents of the boiler at an even temperature, should that of the iirer chamber vary.

It has been found by actual experiment that sufficient heat is absorbed by the tiling and imparted to the boiler to generate steam sufficient to run an engine for hours after the fire upon the grate-bars has been withdrawn or died out.

Having thusy described my invention, what I claim, and desire to secure by Letters Patent, is*

1. The combination, with a steam-boiler, of a lining of tiling having plain concavo-convexed faces corresponding With and suspended by the boiler in close and direct contact with the boiler over the fire-chamber, substantially as described. Y

2. The combination, with a steam-boiler, of a perforated lining conforming in shape to and suspended in close contact with the entire con-l tiguous surface of the boiler, said perforations forming air-inlets not having Contact with the boiler, substantially-as described.

3. A lining for stearnboilers, concavoconveX in form, held in contact with the boiler, and provided with a series of perforations, forming airinlets, terminating in elbow-tubes, substantially as described.

4. rlhe combination, with a steam-boiler, of a perforated concavo-convex lining suspended in contact with the same over the fire-chamber, and of a perforated side lining for the firechamber, substantially as described.

CHARLES MOMILLAN.

Vitn esses:

JNO. G. ELLIOTT, S. S. Scnorr. 

